{ INFORMATICS.MCCME.RU
  Problem statement: http://informatics.mccme.ru/moodle/mod/statements/view3.php?chapterid=302
  Verdict: Accepted
}
uses SysUtils, Math;
 
var
	a,b,c,ss,kk,tt:int64;
 
begin
reset(input,'input.txt');
rewrite(output,'output.txt');
read(a,b,c);
if (a+b>c) and (a+c>b) and (b+c>a) then begin
	ss:=a+b+c;
	kk:=min(a,min(b,c));
	tt:=max(a,max(b,c));
	dec(ss,kk);
	dec(ss,tt);
	if kk*kk+ss*ss=tt*tt then write('right') else 
	if kk*kk+ss*ss<tt*tt then write('obtuse') else write('acute');	
end else write('impossible');
end.